diff --git a/libraries/libesmtp/slack-desc b/libraries/libesmtp/slack-desc
index 139aee4dc6..1bed967c5f 100644
--- a/libraries/libesmtp/slack-desc
+++ b/libraries/libesmtp/slack-desc
@@ -1,3 +1,11 @@
+# HOW TO EDIT THIS FILE:
+# The "handy ruler" below makes it easier to edit a package description.  Line
+# up the first '|' above the ':' following the base package name, and the '|'
+# on the right side marks the last column you can put a character in.  You must
+# make exactly 11 lines for the formatting to be correct.  It's also
+# customary to leave one space after the ':'.
+
+      |-----handy-ruler------------------------------------------------------|
 libesmtp: libesmtp (A library for posting Electronic Mail)
 libesmtp: 
 libesmtp: LibESMTP is a library to manage posting (or submission of)